Electrostatic ion beam trap

An electrostatic ion beam trap ( English Electrostatic Ion Beam Trap , EIBT) is an ion trap , in which electrically charged particles (eg. As atoms or molecules) are stored as a fast beam by an electrostatic field.

functionality

In the most common design of the electrostatic ion beam trap, ions with a kinetic energy of a few keV are reflected back and forth between two electrostatic mirrors. Electrostatic lenses ensure that the beam is focused in the radial direction. The ions to be stored are often injected into the trap as a pre-accelerated beam from an ion source on the axis of the trap, while the operating voltages of the ion mirror on the inlet side are switched off. In the time it takes for the ions to reach the entrance mirror again after being reflected at the other mirror, its voltages are switched on so that the ions are trapped between the two mirrors. Sometimes the ions to be stored are only generated in the trap by z. B. Molecules from a gas beam that passes through one of the mirrors near the turning point, are ionized by a laser.

Electrode setup for one of the two electrostatic mirrors of the CTF beam trap at the Max Planck Institute for Nuclear Physics in Heidelberg.

This arrangement is very similar in its functionality to an optical resonator and is therefore sometimes also referred to as an ion resonator . The term multi-turn time of flight mass spectrometer is also often found . There are also special designs in the z. B. the lenses are integrated into the mirror and form electrostatic parabolic mirrors. An electrostatic ion beam trap is also known in which the forward and the returning beam are spatially separated by electrostatic deflectors. Electrostatic ion beam traps can therefore also be viewed as a special form of ion storage ring and can often be described using the same mathematical formalisms.

Applications

Electrostatic ion beam traps are mainly used in research, on the one hand as a mass spectrometer, on the other hand to store ions over a longer period of time during experiments.

Web links

Markus Eritt, Robert Wolf, Martin Breitenfeldt, Alexander Herlert, Gerrit Marx, Lutz Schweikhard: Electrostatic ion trap for mass separation at ISOLTRAP (PDF; 56 kB). Ernst Moritz Arndt University of Greifswald, accessed May 28, 2013.

Hellmuth Nordwig: Israeli researchers simulate space chemistry in the laboratory . Deutschlandradio 2007.

Individual evidence

↑ D. Zajfman, O. Heber, L. Vejby-Christensen, I. Ben-Itzhak1, M. Rappaport, R. Fishman, and M. Dahan: Electrostatic bottle for long-time storage of fast ion beams. In: Physical Review A: Atomic Molecular and Optical Physics 55, 1997, pp. R1577-R1580, doi : 10.1103 / PhysRevA.55.R1577 .
^ J. Bernard, G. Montagne, R. Brédy, B. Terpend-Ordacière, A. Bourgey, M. Kerleroux, L. Chen, HT Schmidt, H. Cederquist, and S. Martin: A “tabletop” electrostatic ion storage ring: mini ring. In: Review of Scientific Instruments 79, 2008, p. 075109, doi : 10.1063 / 1.2957609 .

[1] D. Zajfman, O. Heber, L. Vejby-Christensen, I. Ben-Itzhak1, M. Rappaport, R. Fishman, and M. Dahan: Electrostatic bottle for long-time storage of fast ion beams. In: Physical Review A: Atomic Molecular and Optical Physics 55, 1997, pp. R1577-R1580, doi : 10.1103 / PhysRevA.55.R1577 .

[2] J. Bernard, G. Montagne, R. Brédy, B. Terpend-Ordacière, A. Bourgey, M. Kerleroux, L. Chen, HT Schmidt, H. Cederquist, and S. Martin: A “tabletop” electrostatic ion storage ring: mini ring. In: Review of Scientific Instruments 79, 2008, p. 075109, doi : 10.1063 / 1.2957609 .